QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6ml

Earthquake near Harper, KS

No earthquake was likely felt in Harper in the 24 hours to 2:43 pm CST (20:43 UTC). The last one was M 3.4, 186 km (116 mi) S, at 5:53 am CST on 7 November 2026, estimated intensity II (weak) in town; 23 felt reports to USGS. Every earthquake near Harper

This page: a magnitude 1.6 earthquake was recorded 17 km (10 mi) east-northeast of Harper, KS, at 8:13 pm CDT on 24 August 2018 (01:13 UTC), 3.0 km deep.

USGS: 7 km NNE of Danville, Kansas

59 km (37 mi) SW of Wichita, KS

8:13 pm CDT, Aug 24, 2018 · · 3.0 km deep · released about 9 lb of TNT

10 km30 km60 km120 km N Harper County 26 kmSumner County 34 kmKingman County 35 kmSedgwick County 51 kmGrant County 62 kmReno County 70 kmBarber County 75 kmAlfalfa County 80 kmPratt County 85 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
8:13 pm CDT on 24 August 2018 ()
Where
17 km (10 mi) east-northeast of Harper, KS · earthquakes near Harper
Magnitude
M 1.6 (ml)
Depth
3.0 km below the surface
Felt
no reports yet
Nearest
Harper County, 26 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3001 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth, people at rest would likely notice it out to about 10 km (6 mi) from the epicentre. In Harper, 17 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Earthquakes near other towns within 30 km: Conway Springs, Anthony.

How big was it?

This earthquake released about 9 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,200,000× the energy of this one
  3. Around the size people start to feel M 3.0 110× the energy of this one
  4. This earthquake M 1.6 about 9 lb of TNT

Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.

For this area

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 37.3453, -97.8537. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Harper County, KS 26 km (16 mi) SW earthquakes near Harper County
Sumner County, KS 34 km (21 mi) ESE earthquakes near Sumner County
Kingman County, KS 35 km (21 mi) NW earthquakes near Kingman County
Sedgwick County, KS 51 km (32 mi) NE earthquakes near Sedgwick County
Grant County, OK 62 km (39 mi) S earthquakes near Grant County
Reno County, KS 70 km (43 mi) NNW earthquakes near Reno County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

58 earthquakes have been recorded within 50 km since this one.

  1. 3.1 7 km NE of Harper, Kansas
  2. 1.6 11 km N of Caldwell, Kansas
  3. 1.5 7 km S of Argonia, Kansas
  4. 1.9 7 km E of Freeport, Kansas
  5. 1.8 7 km S of Argonia, Kansas
  6. 1.7 7 km S of Argonia, Kansas
  7. 2.8 7 km S of Argonia, Kansas
  8. 3.7 7 km E of Freeport, Kansas
  9. 2.4 8 km NNE of Danville, Kansas
  10. 2.6 10 km N of Harper, Kansas
  11. 1.9 4 km E of Bluff City, Kansas
  12. 1.7 6 km ENE of Harper, Kansas
  13. 1.8 7 km NNE of Danville, Kansas
  14. 2.3 7 km NE of Danville, Kansas
  15. 2.1 6 km NE of Danville, Kansas

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.